Stay strip



Mar h 11, 1958 F. HOLTKAMP 2,826,352

STAY STRIP Filed March 22, 1954 INVENTOR. CLIFFORD E HoLT/rnMP Alla/7g United States Patent STAY STRIP Clilford F. Holtkamp, Cincinnati, Ohio, assignor, by

mesne assignments, to Kamp Company, Inc., Cincinnati, Ohio, a corporation of Ohio Application March 22, 1954, Serial No. 417,841 6 Claims. (Cl. 229-49) This invention relates to improvements in a stay strip such as employed for connecting adjacent edges of the corners of the walls of card or paper board boxes or cartons or for the reinforcement of the said boxes or cartons corners whose walls are otherwise joined.

This application discloses improvements in such a stay strip over that disclosed in applicants application, Serial No. 200,669, filed December 13, 1950, for Metal Strip for Staying Boxes, now Pat. No. 2,728,514.

As was pointed out in the above application, stay strips have been known but had inherent weaknesses in some instances, since they were either formed as portions of an apertured loop which resulted in a structure whose edge was easily distorted rendering same diflicult of use in the machine for applying same, or the loop material around the aperture, and from which the lugs depended, caused a complete severing of the material within the aperture from the box wall and, therefore, a separation of the stay strip from the said box wall. Another form of stay strip had the prongs indented from the edge of the strip metal, but were flat transversely of the prong and resulted in the prong not always bending or clinching properly and frequently resulted in the prong bending and clinching before it entered the box material.

In the above identified application the stay is provided 'witha plurality of prongs each of which has a transverse contour other than plane or flat to overcome the diificulty of past constructions in strengthening the said prong against bending or clinching prior to being driven home. The said structure of the above identified application has been very successful, but the structure of this application has been developed to further strengthen the said stay' strip prong and further insure the said stay strip.

The principal object of the present invention, there fore, is the provision ,of a stay strip having prongs inwardly of the edge of the strip with the body portion of the prong depending from the strip and transversely contoured to supply same with the maximum in rigidity while being produced at a minimum of cost and in the most expeditious manner.

Another object of this invention is the provision of a stay strip formed from strip stock having along each edge of said strip stock indentations each of which provides a pair of depending prongs with each prong transversely contoured for rigidity.

A further object of this invention is the provision of a stay strip for accomplishing the foregoing objects and in which a portion of the original edge of the strip material remains between adjacent indentations whereby substantially continuous edges are provided on the strip which is employed in protecting the stay strip while in transit and in connection with the machine for applying said stay strip to boxes, cartons and the like.

Other objects and advantages of the present invention should be readily apparent by reference to the following proper operation of the specification considered in conjunction with the accompartying drawings forming a part thereof and it is to be ice understood that any modifications may be made in the exact structural details there shown and described, Within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

In the drawings:

Fig. 1 is a fragmentary perspective view of a corner a box showing the stay strip of this invention in use. Fig. 2 is a plan view of the face side of a piece of strip material formed in accordance with this invention to provide stay strips for boxes.

Fig. 3 is a bottom plan view of the stay strip material illustrated in Fig. 2.

Fig. 4 is an edge view of the stay strip material illustrated in Fig. 2.

Fig. 5 is a staggered transverse sectional view through the stay strip material as seen from line 55 on Fig. 2.

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts.

A box stay strip represents a small section cut from a roll of stay strip material at the time that it is applied to the box or carton. The said stay strip material is supplied to the so-called staying machine in a roll of several hundred feet and a section of said stay strip material is illustrated in Figs. 2, 3 and 4 of the drawings. The actual length of a stay strip depends upon the depth of the box or carton, that is, the height of the wall and will include two or more sets of prongs as will presently be made clear.

As illustrated in Fig. 2 the material or metal strip 10 is provided on one side thereof with a plurality of indentations 11 with each indentation 11 transveresely aligned with a similar indentation 12. The indentations 11 and 12 are substantially identical in construction and are each formed to embrace slightly more than a half circle.

In order that the said indentations include more than a half circle, the arc of the circle is generated about a line or point inwardly of the edge of the material. Specifically, the material or metal strip 10 is provided with longitudinal edges 13 and 14 which are parallel, or substantially so, from end to end of the strip and it is Since each indentation 11 is transversely aligned with an indentation 12, the said indentations are formed around a line 15 with the center or point of generation of each indentation located on said line 15. To form the indentation to a true semi-circle, the point of generation on the line 15 would be where the edge, 13 or 14 crosses said line 15 while to generate the said indentation to embrace somewhat more than a true semi-circle, the point of generation would be inwardly of the said edges of the metal strip. The location of the point of generation for the indentation 11 is indicated where the line 16 crosses the line 15 while the point of generation for the indentation 12 is indicated where the line 17 crosses said line 15. The lines 18 and 19, respectively, indicate the radius of the indentations 11 and 12, respectively, from its point of generation on the center line 15 of the indentations. From this it will be readily understood that the said indentations 11 and 12 each embrace an area greater than a half circle of a radius such as indicated by either of the lines 18 or 19.

It will be noted that each indentation 11 and 12 has, therefore, a face 20 that is truly circular and generated or formed about a point as an axis.

In the formation of the indentations 11 and 12 the material in each said indentation is downwardly bent and the said material, in the process of forming the indentation and the downwardly bending of the same, is split substantially on the line 15 with the result that a pair of lugs 21 and 22 is formed in each indentation 11 and 12 to depend from the material or metal strip 10. Furthermore, each depending prong is provided with a point 23 which coincides with the point where the center line 15 of the indentation crosses the edge 13 or.14 of the metal strip and each prong is provided witha body portion 2 4 that is substantially triangular in plan. The edges of the triangular body portion 24 of each prong diverge from the point 23 to the outer edge thereof, or to' its half of the indentation from the center thereof, all as" clearly illustrated in Fig. 4. L 1

Each of the prongs has its upper end, or base, integral with the metal strip and adjacent prongs bases constitute or form the circular face 20Tof its indentation, wherefore, the said base of each prong is transversely rounded or arced in accordance withthe arcuate formation of the indentation face, or arce'd to a radius as represented by the line 19.

The center lines 15 of adjacent indentations are spaced 7 from one another a 'distancegreate'r' than the diameter of said indentations, wherefore, a portion 25 of each edge of the strip material remains between adjacent indentations. These remaining portions 25 of the original edges of the material protect the strip from damage 'after it is coiled from the producing machine and during transportation of the coil to the staying machine. It has been found that coils of staying strips may be stacked on one another without damage and the said coils subsequently used in the stayer, or staying machine.

In the formation of the stay strip, the prongs 21 and 22 are slightly biased inwardly of the edges 13 and 14 of the stay or metal strip 19, as indicated at 26 and 27 in Fig. 5. By this construction, the said prongs are biased in the direction they are eventually bent or clinched in being applied to the box wall for thereby clamping the box wall material between themselves and the body portion of the metal strip. 7

As noted above, Fig. 1 illustrates a box stay in operation which specifically is as follows:

The box includes a base or bottom 28 from adjacent sides of which upstand walls 2? and 3G. The walls have adjacent ends which are in contact with one another to form the box corner and are to be retained in these positions, wherefore, use is made of a metal stay 31 formed from a portion of the material illustrated in Figs. 2, 3, and 4. The box stay is bent along a substantially central axis midway between the strip edges 13 and 14 so as to lie in close contact with the right angle faces of the box walls at the corner thereof.

In order to assist in the bending of the stay on its longitudinal axis the material or metal strip 10 is provided longitudinally centrally thereof throughout its length with apertures 32 and with each aperture 32 midway between adjacent aligned indentations 11 and 12.

Asnoted above, a box stay is cut from the strip material and the said out is made between adjacent indentations 11 and 12 with said out conveniently passing through an aperture 32 for thereby supplying each stay with true ends that closely engage the box walls, as clearly illustrated in Fig. l.

From the foregoing it will be appreciated that there has been provided a box stay in which use is made of a depending prong from each edge of the stay material with each depending prong having a transverse curve or transversely arched, in the manner of a corrugation, for thereby materially strengthening said prong against transverse bending or clinching, except under suitable and desirable conditions. prongs, while strengthened against undesirable bending or clinching, are biased in the direction of the desired bending or clinching and which proper bending or clinching is effected by the anvils of the stay attaching machine, a machine and method of attaching which are well-known in the art.

' 4 What is claimed is:

l. A stay strip formed from sheet metal having longitudinally parallel edges, a plurality of indentations inwardly from each of the said edges of the strip with each indentation formed circularly around a point on a center line that is substantially normal to its edge and with said point inwardly of the edge of the strip, each indentation having a circular face slightly greater than a half circle with the material of each indentation on each side of said center line downwardly bent, and a depending prong on each side of the center line of each indentation formed from the said downwardly bent material with each prong having a point and a body portion extending from said point substantially triangular in plan with its base integral with the strip, and adjacentprong bases of each indentation forming the face of the indentation and each prong body portion transversely curved in accordance with the curvature of the face of the indentation.

2. A stay strip formed from sheet metal having longitudinally parallel edges, a plurality of indentations inwardly from each of the said edges of the strip with Furthermore, it will be noted that the said each indentation formed circularly around a point on a center line that is substantially normal to its edge and with said point inwardly of the edge of the strip, each indentation having a circular face slightly greater than a half circle with the material of each indentation on each side of said center line downwardly bent, and a depending prong on each side of the center line of each indentation formed from the said downwardly bent material with each prong having a point and a body portion extending from said point substantially triangular in plan with its base integral with the strip, and each prong inclining inwardly from its base, and adjacent prong bases of each indentation forming the face of the indentation and each prong body portion transversely curved in accordance with the curvature of the face of the indentation.

3. A stay strip formed from sheet metal having substantially parallel edges, a plurality of indentations inwardly from each of the said edges of the strip with each indentation formed circularly around a point on a center line that is substantially normal to its edge and with said point inwardly of the edge of the strip, each indentation having a circular face slightly greater than a half circle with the'material of each indentation on each side of said center line downwardly bent, said indentations being equally spaced from one another along each edge of the material with said spacing of the indentations center lines being greater than the diameter of the indentation as measured along the edge of the material so that a portion of each edge of the material remains between adjacent indentations, and a depending prong on each side of the center line of each indentation formed from the said downwardly bent material with each prong having a point and a body portion extending from said point substantially triangular in plan with its base integral with the strip, and adjacent prong bases of each indentation forming the face of the indentation and each prong body portion transversely curved in accordance with the curvature of the face of the indentation.

4. A stay strip formed from sheet metal having longitudinally parallel straight edges, a plurality of indentations inwardly from each of the said edges of the strip with each indentation formed circularly around a point on a center line that is substantially normal to its edges 'and with said point inwardly of the edge of the strip,

each indentation having a circular face slightly greater than a half circle with the material of each indentation on each side of said center line downwardly bent, said indentations being equally spaced from one another along each edge of the material and said indentations being opposite one another transversely of the strip with said spacing of the indentations center lines being greater than the diameter of the indentation as measured along the edges of the strip so that portions of the original edges of the strip remain between adjacent indentations with said portions of the original strip edges joining adjacent ends of adjacent indentations, and a depending prong on each side of the center line of each indentation formed from the said downwardly bent material with each prong having a point and a body portion extending from said point substantially triangular in plan with its base integral with the strip, and adjacent prong bases of each indentation forming the face of the indentation and each prong body portion transversely curved in accordance with the curvature of the face of the indentation.

5. A stay strip formed from sheet metal having longitudinally parallel straight edges, a plurality of indentations inwardly from each of said edges of the strip with each indentation formed circularly around a point on a center line that is substantially normal to its edge of the strip and with said point inwardly of the edge of the strip, each indentation having a circular face slightly greater than a half circle with the material of each indentation on each side of said center line downwardly bent, said indentations being equally spaced from one another along each edge of the material and said indentations being opposite one another transversely of the strip with said spacing of the indentations center lines being greater than the diameter of the indentation as measured along the edges of the strip so that portions of the original edges of the strip remain between adjacent indentations and with said portions of the original strip edges joining adjacent ends of adjacent indentations, said strip being longitudinally apertured substantially centrally thereof with said apertures, respectively, transversely aligned with the transversely aligned remaining portions of the original strip edges between indentations, and a depending prong on each side of the center line of each indentation formed from the said downwardly bent material with each prong having a point and a body portion extending from said point substantially triangular in plan with its base integral with the strip, and adjacent prong bases of each indentation forming the face of the indentation and each prong body portion transversely curved in accordance with the curvature of the face of the indentation.

6. A stay strip formed from sheet metal having longitudinally parallel straight edges, a plurality of indentations inwardly from each of said edges of the strip with each indentation formed circularly around a point on a center line that is substantially normal to its edge of the strip and with said point inwardly of the edge of the strip, each indentation having a circular face slightly greater than a half circle with the material of each indentation on each side of said center line downwardly bent, said indentations being equally spaced from one another along each edge of the material and said indenta tions being opposite one another transversely of the strip with said spacing of the indentations center lines being greater than the diameter of the indentation as measured along the edges of the strip so that portions of the original edges of the strip remain between adjacent indentations and with said portions of the original strip edges joining adjacent ends of adjacent indentations, said strip being longitudinally apertured substantially centrally thereof with said apertures, respectively, transversely aligned with the transversely aligned remaining portions of the original strip edges between indentations, and a depending prong on each side of the center line of each indentation formed from the said downwardly bent material with each prong having a point and a body portion extending from said point substantially triangular in plan with its base integral with the strip and each prong inclining inwardly from its base, and adjacent prong bases of each indentation forming the face of the indentation and each prong body portion transversely curved in accordance with the curvature of the face of the indenta' tron.

References Cited in the file of this patent UNITED STATES PATENTS 699,894 Partzsch May 13, 1902 1,918,992 Stanger July 18, 1933 2,316,978 Schneeberger Apr. 20, 1943 2,728,514 Holtkamp Dec. 27, 1955 FOREIGN PATENTS 3,105 Great Britain 1898 417,536 Great Britain Oct. 8, 1934 495,606 Great Britain Nov. 16, 1938 

